This invention relates to routing packets, and more particularly to proxy-less packet routing between private and public address realms.
Routing packets involves transferring packets (i.e. pieces of information) between computers in a computer network. A packet includes a data field and an address field. The address field specifies a destination address for which that packet is intended. The address field also specifies a source address from which the packet originated.
Computer networks include computers having a private address and/or a public address. Computers having a private address are in a private network and considered part of a private address realm. Typically, a Request for Comment 1918 (“RFC 1918”) standard defines reserved private IP address spaces in the private realm. Computers having a public address are in the public network and considered part of the public address realm.
Computers in a private network are able to route packets to other computers within that private network using the private address realm. Computers in the public network are able to route packets to other computers within the public network using the public address realm. Computers in private and public networks are only able to transfer packets between each other through a gateway between the networks.
Network Address Translation (“NAT”) is a protocol that enables Internet Protocol (“IP”) computers in a private address realm to transfer packets with IP computers in the public address realm.